1. Field of the Invention
This invention relates to electric power-generating devices, such as wind turbines and ocean current turbines, and more particularly to an electric generator particularly suited to being housed in a turbine nacelle of a horizontal axis, axial flow, wind or water turbine.
2. Prior Art
In a typical horizontal-axis wind turbine, a nacelle is mounted on a tall vertical tower. The nacelle houses power-transmitting mechanisms, electrical equipment and supports a rotor system at one end. Rotor systems for horizontal-axis wind turbines ordinarily include one or more blades attached to a rotor hub on a shaft. Wind flow turns the rotor, which turns a main shaft in the nacelle. The shaft turns gearbox gears that transmit torque to an electric generator. The nacelle typically pivots about the vertical tower to take advantage of wind flowing from any direction. The pivoting about this vertical-axis in response to changes in wind direction is known as yaw or yaw response and the vertical-axis is referred to as the yaw-axis. As wind moves past the blades with enough speed the rotor system rotates and the wind turbine converts the wind energy into electrical energy through the generator. An electrical output of the generator is connected to a power grid.
Generators used in wind turbines are customarily connected to the gearbox output shaft with a flexible coupling. The generator is mounted on a support structure and is shimmed or adjusted by screws to align the generator to the gearbox.
Due to the flexibility of very large platforms, the coupling is expanded to a coupling and jackshaft to accommodate deflection. The generator rotor is supported by bearings located in the generator frame and requires lubrication on a regular schedule.
It is therefore desirable to provide a generator mounting system that eliminates couplings.
It is also desirable to provide a wind turbine generator that is easy to mount and de-mount in a nacelle that is located atop a tall tower.
It is also desirable to provide a wind turbine generator that provides perfect or near perfect alignment of air gap.
It is also desirable to provide a wind turbine generator that provides cost savings by using a labyrinth seal that doubles as a magnet protector.